Field of the Invention
The present invention relates to a multilayer ceramic capacitor constituted by a capacitor body and external electrodes of roughly L shape provided on the opposing ends thereof.
Description of the Related Art
One known mode of external electrodes provided on the opposing ends of a multilayer ceramic capacitor is that the external electrodes each have a roughly L shape having a part along one length-direction face, and a part along one height-direction face, of the capacitor body (refer to Patent Literature 1 mentioned below). The multilayer ceramic capacitor disclosed in Patent Literature 1 mentioned below (hereinafter referred to as “conventional multilayer ceramic capacitor”) comprises: a capacitor body having a first face and a second face that are facing each other in the length direction, a third face and a fourth face that are facing each other in the width direction, and a fifth face and a sixth face that are facing each other in the height direction; a first external electrode of roughly L shape having a first part along the first face, and a second part along the fifth face, of the capacitor body; and a second external electrode of roughly L shape having a first part along the second face, and a second part along the fifth face, of the capacitor body. The capacitor body has a built-in capacitive part constituted by multiple first internal electrode layers and multiple second internal electrode layers stacked alternately with dielectric layers in between. An end of each of the multiple first internal electrode layers is connected to the first part of the first external electrode. Also, an end of each of the multiple second internal electrode layers is connected to the first part of the second external electrode.
The conventional multilayer ceramic capacitor has a roughly L shape, where neither the first external electrode nor the second external electrode has any part along the sixth face, any part along the third face, or any part along the fourth face, of the capacitor body. This means that, compared to a multilayer ceramic capacitor of the same external dimensions (length, width and height) that uses U-shaped external electrodes, each having a part along the sixth face, the conventional multilayer ceramic capacitor allows the height-direction dimension of its capacitor body to be designed larger by the thickness of the part along the sixth face. Also, compared to a multilayer ceramic capacitor of the same external dimensions that uses external electrodes of square cylinder shape with bottom, each having a part along the sixth face, a part along the third face, and a part along the fourth face, the conventional multilayer ceramic capacitor allows the height-direction dimension and width-direction dimension of its capacitor body to be each designed larger by the thickness of the part along the sixth face, thickness of the part along the third face, and thickness of the part along the fourth face. In other words, the number of internal electrode layers and the area of the internal electrode layer can be increased based on a dimensional expansion of the capacitor body, which contributes to capacitance increase.
Concerning the aforementioned capacitance increase, attempts have been made to use a dielectric ceramic of high dielectric constant associated with high relative permittivity, as the material for the capacitor body except for the first internal electrode layer and second internal electrode layer; however, use of a dielectric ceramic of high dielectric constant causes the DC bias characteristics of the multilayer ceramic capacitor itself to worsen, and this causes the effective capacitance to drop significantly when a direct-current voltage higher than the rated voltage is applied.